16. _______ medicine works in a human body is a question _______ not everyone can understand fully.
Instead of telling the joke he _______, Crystal made up a new one.
I am pleased to have this chance today ______to you about the United Nations or the UN.
—Howareyougettingonwithyourwork? —Oh,I'msorry.Thingsaren'tgoingsowellas________.
Go and make someone laugh —______just might help them live longer.
The visiting European architects showed great ______ for the ancient Chinese building designs in the Forbidden City.